Merge tag 'trace-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "Most of the changes were largely clean ups, and some documentation.
  But there were a few features that were added:

  Uprobes now work with event triggers and multi buffers and have
  support under ftrace and perf.

  The big feature is that the function tracer can now be used within the
  multi buffer instances.  That is, you can now trace some functions in
  one buffer, others in another buffer, all functions in a third buffer
  and so on.  They are basically agnostic from each other.  This only
  works for the function tracer and not for the function graph trace,
  although you can have the function graph tracer running in the top
  level buffer (or any tracer for that matter) and have different
  function tracing going on in the sub buffers"

* tag 'trace-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (45 commits)
  tracing: Add BUG_ON when stack end location is over written
  tracepoint: Remove unused API functions
  Revert "tracing: Move event storage for array from macro to standalone function"
  ftrace: Constify ftrace_text_reserved
  tracepoints: API doc update to tracepoint_probe_register() return value
  tracepoints: API doc update to data argument
  ftrace: Fix compilation warning about control_ops_free
  ftrace/x86: BUG when ftrace recovery fails
  ftrace: Warn on error when modifying ftrace function
  ftrace: Remove freelist from struct dyn_ftrace
  ftrace: Do not pass data to ftrace_dyn_arch_init
  ftrace: Pass retval through return in ftrace_dyn_arch_init()
  ftrace: Inline the code from ftrace_dyn_table_alloc()
  ftrace: Cleanup of global variables ftrace_new_pgs and ftrace_update_cnt
  tracing: Evaluate len expression only once in __dynamic_array macro
  tracing: Correctly expand len expressions from __dynamic_array macro
  tracing/module: Replace include of tracepoint.h with jump_label.h in module.h
  tracing: Fix event header migrate.h to include tracepoint.h
  tracing: Fix event header writeback.h to include tracepoint.h
  tracing: Warn if a tracepoint is not set via debugfs
  ...

1 files changed, 102 insertions, 41 deletions

diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index 38fe1483c508..5b781d2be383 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -13,32 +13,106 @@
 #include <linux/debugfs.h>
 #include <linux/uaccess.h>
 #include <linux/ftrace.h>
+#include <linux/slab.h>
 #include <linux/fs.h>
 
 #include "trace.h"
 
-/* function tracing enabled */
-static int                      ftrace_function_enabled;
+static void tracing_start_function_trace(struct trace_array *tr);
+static void tracing_stop_function_trace(struct trace_array *tr);
+static void
+function_trace_call(unsigned long ip, unsigned long parent_ip,
+                    struct ftrace_ops *op, struct pt_regs *pt_regs);
+static void
+function_stack_trace_call(unsigned long ip, unsigned long parent_ip,
+                          struct ftrace_ops *op, struct pt_regs *pt_regs);
+static struct ftrace_ops trace_ops;
+static struct ftrace_ops trace_stack_ops;
+static struct tracer_flags func_flags;
+
+/* Our option */
+enum {
+        TRACE_FUNC_OPT_STACK    = 0x1,
+};
+
+static int allocate_ftrace_ops(struct trace_array *tr)
+{
+        struct ftrace_ops *ops;
+
+        ops = kzalloc(sizeof(*ops), GFP_KERNEL);
+        if (!ops)
+                return -ENOMEM;
 
-static struct trace_array       *func_trace;
+        /* Currently only the non stack verision is supported */
+        ops->func = function_trace_call;
+        ops->flags = FTRACE_OPS_FL_RECURSION_SAFE;
+
+        tr->ops = ops;
+        ops->private = tr;
+        return 0;
+}
+
+
+int ftrace_create_function_files(struct trace_array *tr,
+                                 struct dentry *parent)
+{
+        int ret;
+
+        /* The top level array uses the "global_ops". */
+        if (!(tr->flags & TRACE_ARRAY_FL_GLOBAL)) {
+                ret = allocate_ftrace_ops(tr);
+                if (ret)
+                        return ret;
+        }
+
+        ftrace_create_filter_files(tr->ops, parent);
+
+        return 0;
+}
 
-static void tracing_start_function_trace(void);
-static void tracing_stop_function_trace(void);
+void ftrace_destroy_function_files(struct trace_array *tr)
+{
+        ftrace_destroy_filter_files(tr->ops);
+        kfree(tr->ops);
+        tr->ops = NULL;
+}
 
 static int function_trace_init(struct trace_array *tr)
 {
-        func_trace = tr;
+        struct ftrace_ops *ops;
+
+        if (tr->flags & TRACE_ARRAY_FL_GLOBAL) {
+                /* There's only one global tr */
+                if (!trace_ops.private) {
+                        trace_ops.private = tr;
+                        trace_stack_ops.private = tr;
+                }
+
+                if (func_flags.val & TRACE_FUNC_OPT_STACK)
+                        ops = &trace_stack_ops;
+                else
+                        ops = &trace_ops;
+                tr->ops = ops;
+        } else if (!tr->ops) {
+                /*
+                 * Instance trace_arrays get their ops allocated
+                 * at instance creation. Unless it failed
+                 * the allocation.
+                 */
+                return -ENOMEM;
+        }
+
         tr->trace_buffer.cpu = get_cpu();
         put_cpu();
 
         tracing_start_cmdline_record();
-        tracing_start_function_trace();
+        tracing_start_function_trace(tr);
         return 0;
 }
 
 static void function_trace_reset(struct trace_array *tr)
 {
-        tracing_stop_function_trace();
+        tracing_stop_function_trace(tr);
         tracing_stop_cmdline_record();
 }
 
@@ -47,25 +121,18 @@ static void function_trace_start(struct trace_array *tr)
         tracing_reset_online_cpus(&tr->trace_buffer);
 }
 
-/* Our option */
-enum {
-        TRACE_FUNC_OPT_STACK    = 0x1,
-};
-
-static struct tracer_flags func_flags;
-
 static void
 function_trace_call(unsigned long ip, unsigned long parent_ip,
                     struct ftrace_ops *op, struct pt_regs *pt_regs)
 {
-        struct trace_array *tr = func_trace;
+        struct trace_array *tr = op->private;
         struct trace_array_cpu *data;
         unsigned long flags;
         int bit;
         int cpu;
         int pc;
 
-        if (unlikely(!ftrace_function_enabled))
+        if (unlikely(!tr->function_enabled))
                 return;
 
         pc = preempt_count();
@@ -91,14 +158,14 @@ static void
 function_stack_trace_call(unsigned long ip, unsigned long parent_ip,
                           struct ftrace_ops *op, struct pt_regs *pt_regs)
 {
-        struct trace_array *tr = func_trace;
+        struct trace_array *tr = op->private;
         struct trace_array_cpu *data;
         unsigned long flags;
         long disabled;
         int cpu;
         int pc;
 
-        if (unlikely(!ftrace_function_enabled))
+        if (unlikely(!tr->function_enabled))
                 return;
 
         /*
@@ -128,7 +195,6 @@ function_stack_trace_call(unsigned long ip, unsigned long parent_ip,
         local_irq_restore(flags);
 }
 
-
 static struct ftrace_ops trace_ops __read_mostly =
 {
         .func = function_trace_call,
@@ -153,29 +219,21 @@ static struct tracer_flags func_flags = {
         .opts = func_opts
 };
 
-static void tracing_start_function_trace(void)
+static void tracing_start_function_trace(struct trace_array *tr)
 {
-        ftrace_function_enabled = 0;
-
-        if (func_flags.val & TRACE_FUNC_OPT_STACK)
-                register_ftrace_function(&trace_stack_ops);
-        else
-                register_ftrace_function(&trace_ops);
-
-        ftrace_function_enabled = 1;
+        tr->function_enabled = 0;
+        register_ftrace_function(tr->ops);
+        tr->function_enabled = 1;
 }
 
-static void tracing_stop_function_trace(void)
+static void tracing_stop_function_trace(struct trace_array *tr)
 {
-        ftrace_function_enabled = 0;
-
-        if (func_flags.val & TRACE_FUNC_OPT_STACK)
-                unregister_ftrace_function(&trace_stack_ops);
-        else
-                unregister_ftrace_function(&trace_ops);
+        tr->function_enabled = 0;
+        unregister_ftrace_function(tr->ops);
 }
 
-static int func_set_flag(u32 old_flags, u32 bit, int set)
+static int
+func_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set)
 {
         switch (bit) {
         case TRACE_FUNC_OPT_STACK:
@@ -183,12 +241,14 @@ static int func_set_flag(u32 old_flags, u32 bit, int set)
                 if (!!set == !!(func_flags.val & TRACE_FUNC_OPT_STACK))
                         break;
 
+                unregister_ftrace_function(tr->ops);
+
                 if (set) {
-                        unregister_ftrace_function(&trace_ops);
-                        register_ftrace_function(&trace_stack_ops);
+                        tr->ops = &trace_stack_ops;
+                        register_ftrace_function(tr->ops);
                 } else {
-                        unregister_ftrace_function(&trace_stack_ops);
-                        register_ftrace_function(&trace_ops);
+                        tr->ops = &trace_ops;
+                        register_ftrace_function(tr->ops);
                 }
 
                 break;
@@ -208,6 +268,7 @@ static struct tracer function_trace __tracer_data =
         .wait_pipe      = poll_wait_pipe,
         .flags          = &func_flags,
         .set_flag       = func_set_flag,
+        .allow_instances = true,
 #ifdef CONFIG_FTRACE_SELFTEST
         .selftest       = trace_selftest_startup_function,
 #endif